A new national survey of Latino immigrants suggests that recently adopted state and local laws aimed at making life more difficult for illegal immigrants have slowed the growth in the flow of money sent to relatives in Mexico.

Experts who follow the money transfers, also known as familial remittances, have been confounded over why growth in the totals has leveled off in the first half of the year despite continued growth in the Mexican immigrant population.

The Inter-American Development Bank sponsored a recent survey of 900 immigrants by Bendixen & Associates, a Miami firm that specializes in multi-cultural polling, to try to explain the change.

The poll found that this year 56 percent of Mexicans living in states with newer immigrant populations sent money to their relatives back home, compared with 80 percent last year.

Many of those are the same states that have passed more than 40 laws in the past two years that created harsh penalties for businesses employing illegal immigrants and landlords who board them. English-only laws also have proliferated.